Shock-and-dig-relieving daggerboard

ABSTRACT

DAGGERBOARD SO SHAPED, MOUNTED WITHIN AND CORRELATED WITH THE BOAT WELL, THAT THE BOARD IN RESPONSE TO IMPINGEMENT OF ITS LOWER END WITH THE BOTTOM SUBMERGED BENEATH THE WATER, OR WITH A SOLID FIXED OBJECT, AUTOMATICALLY PIVOTS ABOUT A TRANSVERSE AXIS FIXED WITH THE WELL, TO THEREBY DECREASE THE NORMAL MAXIMUM PRO-   JECTION OF THE BOARD. YIELDING MEANS CONTINUOUSLY URGES THE BOARD INTO NORMAL OPERATING POSITION. THE BOARD MAY ALSO BE MANUALLY ELEVATED OUT OF THE WELL FOR ALL POSITIONS OF PIVOTING THEREOF ABOUT THE AFORESAID AXIS.

Much 23, 1-971 E. c. SMOOT, JR SHOCK-AND-DIG-RELIEVING DAGGERBQARD FiledMarch 11, 1969 IN vazv roR J (seal) United States Patent 3,572,279SHOCK-AND-DllG-RELIEVING DAGGERBOARD Ernest Clyde Smoot, Jr., 6218Dustin Drive, Richmond, Va. 23226 Filed Mar. 11, 1969, Ser. No. 806,081Int. Cl. B6311 41/00 US. Cl. 114-132 8 Claims ABSTRACT OF THE DISCLOSUREDaggerboard so shaped, mounted within and correlated with the boat well,that the board in response to impingement of its lower end with thebottom submerged beneath the water, or with a solid fixed object,automatically pivots about a transverse axis fixed With the well, tothereby decrease the normal maximum projection of the board. Yieldingmeans continuously urges the board into normal operating position. Theboard may also be manually elevated out of the well for all positions ofpivoting thereof about the aforesaid axis.

This invention relates to improvements in a sailboat keel commonly knownas a daggerboard which is specifically a keel board without a pivot pinand which passes through the sailboat by means of a box, trunk or wellbuilt in the boat. This is to differentiate from the usual centerboardwith pivot pin.

This invention relates more specifically to improvements in the type ofkeel commonly known as a dagger board, by way of cutting away a certainportion of the daggerboard within the Well, cutting a certain bevel onthe lower end of the board, and adding a Spring mechanism and handle tothe top of the daggerboard as specified. This improvement permits thedaggerboard to pivot about an imaginary pivot at the rear of thedaggerboard well. Daggerboards have not before this invention beenconsidered to pivot. This invention has no pivot pin as is a commonfactor in a centerboard. This invention is an improvement in the art ofdaggerboard mechanisms, as it can be fitted to any existing or newrectangular daggerboard well in existing or new boats.

The objective of this invention is to provide a pivoting daggerboard andmechanism which can be slipped downward into any daggerboard well usingthe rectangular width and length as specified by any sailboat design toprovide sufficient lateral water resistance for the boat, the board tofit into a well with parallel fore and aft ends, which is the commondesign in the art, this board so fitted is to allow the bottom-most partof the board to move toward the rear of the boat with the tip end risingslightly from its down position, all of this when striking an object orbottom of waterway, and from this pivoted-back position to allowdaggerboard to be pulled up through the well without returning the boardto the original draft extreme.

A further objective is to relieve the Suddenness with which the sailboatwould stop when striking an object with the board and thus causing theboat occupants to fall or be pitched forward were it not for this shapeof the daggerboard with spring mechanism.

A further objective is to prevent the board from digging as tightly as afull draft board upon striking soft bottoms.

Other objectives and advantages of the invention will be apparent fromthe following description and from the drawing forming a part thereof.

The drawing shows a preferred embodiment of the invention and suchembodiment will be described, but it will be understood that variouschanges may be made from the construction disclosed, and that thedrawing ice and description are not to be construed as defining orlimiting the scope of the invention, the claims forming a part of thisspecification being relied upon for that purpose.

Turning now to the drawing, this invention can be represented by onefigure With dotted lines showing moved position.

The reference numeral 1 is a daggerboard which is a sheet of plywood,processed wood, plastic or metal. 2 is the open-bottom edge of aconventional rectangular daggerboard well of any sailboat. 3 and 4respectively are the fore and aft ends of any conventional daggerboardwell. 5 is the open-top edge of any daggerboard Well. The dimensions of2, 3, 4 and 5 can be varied indefinitely provided 3 approximately equals4 and 2 approximately equals 5 in every configuration. The edge 6 showsthat the elevational shape of daggerboard 1 has been cut away along aline drawn from point 7 to point 8. Point 8 is located on the originalfront edge 9 of the rectangular panel from which daggerboard 1 is sawnout. Point 8 is where front edge 9 of panel intersects the open bottomedge 2 of the well. Point 7 is a point .15 of the length of the top edge10 ofthe original rectangular panel measuring along 10 from point 14,where 10 and rear edge 11 intersect.

The bottom end 12 of daggerboard 1 is sawn on a slope determined byplacing a construction angle with its angle lying atop the originalrectangular panel, shown by lines 9, 10, 11 and 13, and then moving thisconstruction triangle so that triangular side 16 passes through thepoint or corner 14 and triangular side 17 passes through corner 15 ofthe original rectangular panel. Now that bottom end 12 of thedaggerboard has been established as a straight line, round line 11 toline 12 to front edge 18 of completed daggerboard 1 and also round line18 to line 6. Use full-round or large curves.

19 is a ball-type knob firmly affixed on shank 20. Shank 20 is threadeddown into top of daggerboard 1. Plate set 21 consists of two wood ormetal plates, one for each side of daggerboard 1, which are fastened toor through the daggerboard to thicken the position where plate set 21 ismounted sufliciently to prevent daggerboard 1 from having the top endslip below well top 5. Lower edge of plate 21 must be rounded as shownto permit movement of the board to its second position. This shape isnecessary to permit the unique motion of the board. 22 is a ring or astrap placed around shank 20. Spring 23 has one end hooked in ring 22and the other end into ring 24 held by metal strap 25. Spring 23 is acoil spring which resists any pull so as to extend its length.

In operation, when the bottom end 12 of daggerboard 1 strikes the bottomof waterway 26, or in the event a submerged object strikes daggerboardedge 18, the board will pivot about point 27 of its well, taking thedottedline position as shown. Suddenness of movement is absorbed byspring 23.

As it is assumed that the bottom of waterway 26 is struck because of arise in the bottom, a second imaginary and operating bottom 28 ofwaterway is shown tangent to moved position of daggerboard 1. The heightof operating bottom 28 above original bottom 26 will vary with everydaggerboard well depth and width.

The purpose of angle edge 6, sawn exactly as hereinbefore expressed, andof bottom end 12, sawn exactly as hereinbefore expressed, is to allowthe operator of the boat to pull daggerboard 1, using handle 19, upwardthrough the well passing upwards between well ends 3 and 4 withoutreturning bottom end 12 of daggerboard to the original bottom ofwaterway 26. The entire daggerboard 1 will move forward and upward fromits second position so that its bottom end 12 will not pass below theoperating bottom of waterway 28, thus lessening the dig-in of the edge12 as the boat operator Works the board up to free himself from the soilbottom of the waterway. The entire daggerboard 1 can be pulled out oftop of the well if desired by unhooking spring 23 at either end.

It should be understood that the herein shown and described form ofdaggerboard and mechanism is intended to exemplify the principles of thepresent invention and that various modifications and rearrangements ofits component parts may be made within the scope of the appended claims,wherein I claim:

1. A daggerboard comprising an essentially rigid planar sheet ofmaterial having an essentially straight aft edge and a lower forwardedge portion parallel with and spaced a fixed distance from said aftedge, said lower forward edge portion extending from the bottom edge ofthe board, to a first point between the top and bottom of the board,said forward edge continuing upwardly and rearwardly from said firstpoint, in a second straight upper portion, to substantial intersectionwith the upper terminal of said aft edge, at a second point, and a pairof rigid pivot plates fixed to and projecting laterally fromrespectively opposite surfaces of said board, contiguous to said secondpoint, said plates having downwardly convex arcuate lower edges intransverse registration, each with the other.

2. The daggerboard of claim 1, said bottom edge extending forwardly andupwardly at an obtuse angle from and with respect to said straight aftedge, the junctions between said aft, bottom, and lower forward edgeportion, being faired curves.

3. The daggerboard of claim 2, said obtuse angle being such that saidbottom edge makes a right angle With a line through said second pointand the extended intersection of said bottom edge with said lowerforward edge portion.

4. The daggerboard of claim 1, in combination, a boat having a wellrectangular in horizontal section, of a transverse width to receive saiddaggerboard with a smooth sliding fit, said well having spaced forwardand aft vertical surfaces intersecting the bottom of the boat, and upperlaterally-spaced parallel fore-and-aft supporting surfaces on oppositesides thereof, said pivot plates resting on said supporting surfaces,respectively, to support said daggerboard within said well.

5. The combination of claim 4, said daggerboard normally having theupper portion of its said aft edge in contact with the aft verticalsurface of the well, and pivoting about the transverse line ofintersection of said aft vertical surface and the boat bottom, by and inresponse to impingement of the lower projecting portion of thedaggerboard with a fixed object, said plates riding on said fore-and-aftsupporting surfaces during pivoting of the board as aforesaid.

6. The combination of claim 5, and means connected between said boat anddaggerboard yieldingly urging the aft edge of the latter into contactwith said aft vertical surface.

7. The combination of claim 6, said last-named means comprising a springhaving one end attached to said daggerboard, adjacent to said secondpoint thereof, and its other end attached to said boat.

8. The combination of claim 5, pivoting of said daggerboard as aforesaidbeing limited by engagement between the second portion of its forwardedge and the forward vertical surface of the well.

References Cited UNITED STATES PATENTS TRYGVE M. BLIX, Primary Examiner

